“The heart-wrenching pain of these victims, which cries out to heaven, was long ignored, kept quiet or silenced.”

Several commentators have deemed it the first time a pope has addressed all Catholics on the topic of sexual abuse.

“We showed no care for the little ones; we abandoned them,” he wrote on Monday. “The heart-wrenching pain of these victims, which cries out to heaven, was long ignored, kept quiet or silenced.”

Pope Francis acknowledged the recent Pennsylvania Grand Jury Report, which detailed the experiences of over a thousand victims of child sexual abuse at the hands of 300 priests in six dioceses in Pennsylvania.

“Looking back to the past, no effort to beg pardon and to seek to repair the harm done will ever be sufficient. Looking ahead to the future, no effort must be spared to create a culture able to prevent such situations from happening, but also to prevent the possibility of their being covered up and perpetuated.”

“To say ‘no’ to abuse is to say an emphatic ‘no’ to all forms of clericalism.”

In 2014, the Pope compared sexual abuse to the performing of a “black mass”, the worship of Satan. In this week’s letter, the Pope called on the Church to join forces to uproot “this culture of death”.

“Without the active participation of all the Church’s members, everything being done to uproot the culture of abuse in our communities will not be successful in generating the necessary dynamics for sound and realistic change.”

The Pope – who is considered an “outsider Pope”, as the first non-European pope in modern times and the first Jesuit pope – continued his attacks on clericalism. He declared that it “helps to perpetuate many of the evils that we are condemning today” by separating priests and the people they are leading.

“To say ‘no’ to abuse is to say an emphatic ‘no’ to all forms of clericalism,” the Pope wrote.

While the Pope expressed “sorrow and shame” and begged “forgiveness for our own sins and the sins of others”, the letter has been criticised for failing to identify a specific plan of action.

But the Pope did call the faithful to prayer and fasting.

“I invite the entire holy faithful People of God to a penitential exercise of prayer and fasting, following the Lord’s command. This can awaken our conscience and arouse our solidarity and commitment to a culture of care that says ‘never again’ to every form of abuse.”